1. Field of the Invention
The present invention relates to a holographic display apparatus.
2. Description of the Related Art
A holographic display apparatus, which can refigure images or display moving images, has been researched to realize it, but has not yet been established. In order to reproduce a stereoscopic image within the visible region, it is necessary to display an interference pattern with a resolution corresponding to a spatial frequency of from 1000 /mm to 3000 /mm. Therefore, where an interference pattern of hologram is recorded and displayed with a photo-sensitive material, such as a photographic film or photographic dry plate, silver halide having a particle diameter of from 50 nm to 60 nm is used to increase the resolution of the pattern.
A method of displaying an interference pattern has been proposed, which utilizes a liquid crystal display device of the reflection type. A display device using liquid crystal has a pixel size as large as 10 .mu.m at least ("TV PICTURE OPTICS HANDBOOK", edited by TV Association, Ohm-Shya, 1980). Due to this, it is difficult to obtain a resolution sufficient to display an interference pattern necessary for reproducing a stereoscopic image within the visible region.
As described above, a fine pixel size has not yet been realized, which provides a display section with a sufficient resolution, in conventional tests to form a holographic display apparatus.